Contactless payment systems facilitate secure payments using short-range communication networks (e.g., near field communication (NFC), radio-frequency identification (RFID), etc.). For instance, contactless payment systems facilitate the exchange of transaction information between a payment instrument (e.g., an EMV payment card, a mobile device executing a payment application, etc.) and a payment terminal over a short-range communication network when the payment instrument and the payment terminal are within a threshold distance of one another. In an example where a customer uses a mobile device as a payment instrument, to alert a customer associated with the payment instrument of a successful transaction, the mobile phone or the payment terminal may provide an indication to the customer. For instance, with APPLE PAY®, a customer's mobile phone may vibrate or beep to confirm that the customer paid correctly. Or, with other payment systems, the payment terminal may output an audible success tone (e.g., a sound generated by a 1500 Hz sine wave for a period of approximately 500 milliseconds) or an audible alert tone (e.g., a double beep generated by a 750 Hz sine wave for a first period of approximately 200 milliseconds and a second period of approximately 200 milliseconds, with approximately 200 milliseconds between the first period and the second period) to provide an indication to the customer regarding the contactless payment.
In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The use of the same reference numbers in different figures indicates similar or identical items or features. Moreover, multiple instances of the same part are designated by a common prefix separated from the instance number by a dash. The drawings are not to scale.